VAPORIZED FUEL TREATING DEVICE FOR INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To provide a vaporized fuel treating device for an internal combustion engine capable of quickly measuring information required for its flow rate control without deteriorating the flow rate control accuracy of fuel-air mixture introduced from a canister to an intake pipe. SOLUTION: In this vaporized fuel treating device, vaporized fuel inside a fuel tank is temporarily adsorped by an adsorbent inside the canister, and at the time of operation of the internal combustion engine, the vaporized fuel adsorped by the adsorbent is released into the intake pipe of the internal combustion engine. A pump is driven, air is distributed through a predetermined throttle, and a differential pressure ΔPO before and after the throttle is detected (S202). Next, a three-position valve is switched, the fuel tank, the canister, and the throttle are communicated, and the fuel-air mixture released from the canister is distributed through the throttle (S203). A differential pressure P1 is detected across the throttle when an elapsed time TD becomes a delayed time CD (S208). Then, a differential pressure ratio P is calculated, and a vaporized fuel concentration C used for flow rate control is calculated from the differential ratio P (S209, 210). COPYRIGHT: (C)2008,JPO&INPIT